// Copyright (C) Use Ink (UK) Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use ink_env::{
    call::{
        utils::{
            ReturnType,
            Set,
        },
        CallBuilder,
        Execution,
        ExecutionInput,
    },
    Environment,
};

/// Trait used as bound for the outputs of ink! trait definition messages.
///
/// # Note
///
/// Indicates that a value of type `T` or an equivalent `CallBuilder`
/// instantiation of an ink! message returning a value of type `T` are
/// returned by the respective ink! trait message.
///
/// The bounds are automatically generated by the `#[ink::trait_definition]`
/// procedural macro.
pub trait ImpliesReturn<T> {}

impl<T> ImpliesReturn<T> for T {}
impl<T, E, CallType, Args> ImpliesReturn<T>
    for CallBuilder<E, Set<CallType>, Set<ExecutionInput<Args>>, Set<ReturnType<T>>>
where
    E: Environment,
{
}

impl<E, CallType, Args> ImpliesReturn<()>
    for CallBuilder<E, Set<CallType>, Set<ExecutionInput<Args>>, Set<()>>
where
    E: Environment,
{
}

impl<Args, RetType> ImpliesReturn<RetType> for Execution<Args, RetType> {}
